From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: with ECARTIS (v1.0.0; list xfs); Mon, 18 Sep 2006 07:51:16 -0700 (PDT) Received: from ext.agami.com (64.221.212.177.ptr.us.xo.net [64.221.212.177]) by oss.sgi.com (8.12.10/8.12.10/SuSE Linux 0.7) with ESMTP id k8IEp3Zd011412 for ; Mon, 18 Sep 2006 07:51:08 -0700 Received: from agami.com ([192.168.168.132]) by ext.agami.com (8.12.5/8.12.5) with ESMTP id k8IEoP2c007361 (version=TLSv1/SSLv3 cipher=EDH-RSA-DES-CBC3-SHA bits=168 verify=NO) for ; Mon, 18 Sep 2006 07:50:25 -0700 Received: from mx1.agami.com (mx1.agami.com [10.123.10.30]) by agami.com (8.12.11/8.12.11) with ESMTP id k8IEoKbF013904 for ; Mon, 18 Sep 2006 07:50:20 -0700 Message-ID: <450EB248.3000108@agami.com> Date: Mon, 18 Sep 2006 20:20:48 +0530 From: Shailendra Tripathi MIME-Version: 1.0 Subject: Re: swidth with mdadm and RAID6 References: In-Reply-To: Content-Type: text/plain; charset=ISO-8859-1; format=flowed Content-Transfer-Encoding: 7bit Sender: xfs-bounce@oss.sgi.com Errors-to: xfs-bounce@oss.sgi.com List-Id: xfs To: cousins@umit.maine.edu Cc: xfs@oss.sgi.com Can you list the output of 1. cat /proc/mdstat 2. the command to create 8+2 RAID6 with one spare ? 3. and output of following: xfs_db -r /dev/md* xfs_db> sb xfs_db> p -shailendra Steve Cousins wrote: > I have a RAID6 array of 11 500 GB drives using mdadm. There is one > hot-spare so the number of data drives is 8. I used mkfs.xfs with > defaults to create the file system and it seemed to pick up the chunk size > I used correctly (64K) but I think it got the swidth wrong. Here is what > xfs_info says: > > =========================================================================== > meta-data=/dev/md0 isize=256 agcount=32, agsize=30524160 > blks > = sectsz=4096 attr=0 > data = bsize=4096 blocks=976772992, imaxpct=25 > = sunit=16 swidth=144 blks, unwritten=1 > naming =version 2 bsize=4096 > log =internal bsize=4096 blocks=32768, version=2 > = sectsz=4096 sunit=1 blks > realtime =none extsz=589824 blocks=0, rtextents=0 > =========================================================================== > > So, sunit*bsize=64K, but swidth=144 and swidth/sunit=9 so it looks like it > thought there were 9 data drives instead of 8. > > Am I diagnosing this correctly? Should I recreate the array and > explicitly set sunit=16 and swidth=128? > > Thanks for your help. > > Steve > ______________________________________________________________________ > Steve Cousins, Ocean Modeling Group Email: cousins@umit.maine.edu > Marine Sciences, 452 Aubert Hall http://rocky.umeoce.maine.edu > Univ. of Maine, Orono, ME 04469 Phone: (207) 581-4302 > >